The present invention relates to an apparatus for interchanging orifice plates for an orifice flowmeter. The term "orifice plate" refers to a plate having a flow restricting aperture, i.e., an orifice.
Typically, orifice flowmeters comprise an orifice plate disposed at an intermediate portion of a pipe channel. Standards are set for such orifice plates as to the shape and dimensions of the orifice, and standardized orifice plates are usable for measuring flow rates without the necessity of calibration. However, a single orifice plate is designed for measuring a specified range of flow rates, such that a change of flow rate range requires use of a different orifice plate. While orifice plates are changed usually by disassembling the fluid pipe, the procedure is cumbersome and takes much time. While experiments are sometimes conducted at frequently altered flow rates in laboratories or the like, changing orifice plates requires a long period of time and is very inefficient. Further when a toxic fluid is passed through the pipe channel, orifice plate changing involves a hazard, must be done with care and therefore requires a very long period of time.